Deep blue, low noise Supercontinuum sources


ITRUS - Intelligent Tapers and Seeding for taming the optical Rogue wave and develop stable deep-blue Supercontinuum light sources

Supercontinuum generation (SCG) is an extreme non-linear process, in which a pulse is spectrally broadened to a range that typically spans the entire visible spectrum and extends into the infrared. Silica fiber based supercontinuum (SC) sources are commercially available from e.g. NKT Photonics A/S. The aim of this project is to develop ultra-stable SC sources with high power in the deep-blue wavelength 340-500 nm. A deep blue spectrum is very desirable and has great commercial potential in areas such as food, medical and biological testing.



Photograph of supercontinuum generation in a photonic crystal fiber

SCG is easily realised in photonic crystal fibres (PCFs) due to unique guiding properties. A PCF consists of a solid core surrounded by an array of air holes; the guiding properties can be tailored by manipulating the structure. The main goal of this project is to extend the spectrum further into the blue by tapering the fibre, that is, gradually making the fibre thinner. 

The general picture of the SCG process is that modulation instability (MI) breaks up the pump pulse into a large number of solitons, that subsequently interact while red-shifting due to the Raman effect and generate dispersive waves (DWs) on the short-wavelength side of the zero-dispersion wavelength.  As the solitons red-shift they see increasing group-velocity dispersion that allows the DWs to catch up, which further leads to a temporal overlap and a blue-shift of the DWs. In a uniform PCF the soliton red-shift eventually slows down, which limits the blue edge. In a taper however, one can decrease the dispersion and enhance the non-linearity, which leads to an increased red-shift of the solitons and thereby an increased blue-shift of the DWs into the deep-blue.

Project period: Maj 2010 – Januar 2014

Funding: DKK 5,760,000

Source: Danish Research Council for Technology and Production Sciences (FTP), ref. 0602-01124B (former ref. 09-070566).


Project Members


External Partners



  1. S.T. Sørensen, C. Larsen, C. Jakobsen, C.L. Thomsen, O. Bang ,“Single-mode pumped high air-fill fraction photonic crystal fiber taper for high-power deep-blue supercontinuum sources”, Opt. Lett. (2014)
  2. C. Larsen, K.P. Hansen, K.E. Mattsson, O. Bang, “The all-fiber cladding-pumped Yb-doped gain-switched laser”, Opt. Express 22, 1490 (2014)
  3. C. Larsen, M. Giesberts, S. Nyga, O. Fitzau, B. Jungbluth, H.D. Hoffmann, O. Bang, “Gain-switched all-fiber laser with narrow bandwidth”, Optics Express 21, 12302 (2013).
  4. C. Larsen, S.T. Sørensen, D. Noordegraaf, K.P. Hansen, K.E. Mattsson, O. Bang, "Zero-dispersion wavelength independent quasi-CW pumped supercontinuum generation", Opt. Commun. 290, 170-174 (2013)
  5. U. Møller, O. Bang, “Intensity noise in normal-pumped picoseconds supercontinuum generation, where higher-order Raman lines cross into the anomalous dispersion regime”, Electron. Lett. 49, 63 (2013).
  6. U. Møller, S.T. Sørensen, C. Jacobsen, J. Johansen, P.M. Moselund, C.L. Thomsen, O. Bang, “Power dependence of supercontinuum noise in uniform and tapered PCFs: erratum”, Opt. Express 20, 23318 (2012)
  7. S.T. Sørensen, C. Larsen, U. Møller, P.M. Moselund, C.L. Thomsen, O. Bang,  “Influence of Pump Power and Modulation Instability Gain Spectrum on Seeded Supercontinuum and Rogue Wave Generation”, J. Opt. Soc. Am. B 29, 2875 (2012)
  8. S.T. Sørensen, C. Larsen, U. Møller, P.M. Moselund, C.L. Thomsen, O. Bang, "The role of phase coherence in seeded supercontinuum generation", Opt. Express 20(20), 22886-22894 (2012)U. Møller, S.T. Sørensen, C. Larsen, P.M. Moselund, C. Jacobsen, J. Johansen, C.L. Thomsen, O.
  9. U. Møller, S. T. Sørensen, C. Larsen, P. M. Moselund, C. Jakobsen, J. Johansen, C. L. Thomsen, and O. Bang, "Optimum PCF tapers for blue-enhanced supercontinuum sources Optical Fiber Technology," Invited, Opt. Fiber Technol., Available online 22 August 2012.
  10. S. T. Sørensen, U. Møller, C. Larsen, P. M. Moselund, C. Jakobsen, J. Johansen, T. V. Andersen, C. L. Thomsen, and O. Bang, "Deep-blue supercontinnum sources with optimum taper profiles – verification of GAM," Opt. Express 20, 10635-10645 (2012).
  11. U. Møller, S. T. Sørensen, C. Jakobsen, J. Johansen, P. M. Moselund, C. L. Thomsen, and O. Bang, ”Power dependence of supercontinuum noise in uniform and tapered PCFs,” Opt. Express 20, 2851-2857 (2012). 
  12. S.T. Sørensen, O. Bang, B. Wetzel, J.M. Dudley, ”Describing supercontinuum noise and rogue wave statistics using higher-order moments,” Opt. Comm. 285, 2451–2455 (2012).
  13. C. Larsen, D. Noordegraaf, P. M. W. Skovgaard, K. P. Hansen, K. E. Mattsson, and O. Bang, "Gain-switched CW fiber laser for improved supercontinuum generation in a PCF," Opt. Express 19, 14883-14891 (2011).
  14. S.T. Sørensen, A. Judge, C.L. Thomsen, and O. Bang, "Optimum tapers for increasing the power in the blue edge of a supercontinuum," Opt. Lett. 36, 816 (2011).



Ole Bang
Professor, Group Leader
DTU Fotonik
+4545 25 63 73